After seven years, don't count on any formal Sept. 11 memorial today at Depository Trust Clearing Corp. — even though it was the sudden shock of vulnerability in 2001 that drove the DTCC, based just blocks from the World Trade Center in Manhattan, to spread out and later open a 450-employee securities processing facility in New Tampa.

Down the road at Tampa's Citigroup campus, the banking giant today will simply host local firefighters and police at a luncheon.

While New York-based Citigroup also will pass on any official 9/11 service, Tampa site president Steve Klovekorn's memo to 3,000 local employees honors six Citigroup colleagues who died at the World Trade Center. And he praises employee efforts to raise money and scholarship funds for families that lost members that day in New York, outside Washington, D.C., or in the Pennsylvania plane crash.

Still too raw to ignore, long enough to sense it's time to move on, the Sept. 11 attacks are forcing area companies with close ties to struggle over how to acknowledge what many consider the country's blackest day.

"It's not quite clear what place in history this will take, and whether to over- or under-memorialize it," says Citigroup spokesman Lou Buccino in Tampa.

"It is," he admits, "a work in progress."

At the DTCC, a firm that clears billions of dollars daily in Wall Street and government securities transactions, Sept. 11, 2001, was a day of grit and quiet fortitude. Sealed off in lower Manhattan after the attacks, 500 employees camped for days in the office and, amid the chaos and fear, managed to settle $280-billion worth of securities trades on 9/11, and $1.8-trillion that week.

The stock markets could not have reopened without the DTCC. (Last year, it processed transactions worth $1,860,000,000,000,000. That's $1.86-quadrillion.)

Other company workers came to the aid of financial firm Cantor Fitzgerald, which lost 658 employees at its headquarters in the north tower and whose vital records littered the debris-strewn streets for blocks. The DTCC helped re-create the records.

DTCC spokesman Stuart Goldstein still speaks of dust-coated co-workers trekking out of Manhattan over the Brooklyn Bridge. Many would be hosed down by firemen trying to remove any asbestos. At Goldstein's commuter train station in Princeton, N.J., 60 cars parked on the morning of Sept. 11 were never claimed.

Both the DTCC and Citigroup have moved gingerly away from formal events marking Sept. 11. At each firm, corporatewide ceremonies began to tail off around 2005.

"Some people were very sensitive on this matter," says Citigroup's Buccino, who says working for such a huge corporation can get tricky.

"Being a global company, we usually have a footprint anywhere there is something happening, be it tsunamis or hurricanes," he says.

Seven years later, don't forget Florida played its own prominent role in 9/11. When airplanes struck the World Trade Center towers, President Bush was in Sarasota sitting in teacher Sandra Daniel's second-grade classroom at Emma E. Booker Elementary School.

And just a few towns down the Gulf Coast, in Venice, three terrorists had recently wrapped up the vital pilot training they would use to pull off the unforgettable events of 9/11.